MPS下改性FA/PU复合材料压缩强度试验研究

Experimental study on compressive strength of fly ash/polyurethane composites modified by silane coupling agent

将不同硅烷偶联剂(KH560)下改性的粉煤灰与聚氨酯复合材料配比,制得聚氨酯/改性粉煤灰复合材料,分析了其在室内压缩过程中应力-应变曲线关系,并进一步探究了分别在0.15%,0.30%,0.45%硅烷偶联剂质量分数下,加入不同质量的改性粉煤灰对复合材料压缩强度与弹性模量的影响。研究结果表明,相同偶联剂质量分数下,改性粉煤灰的掺入量并不一定是呈线性增加,复合材料会发生“饱和”现象,过多的改性粉煤灰会组织扩链反应的延续,影响复合材料内部结构,进而影响其压缩性能,应力应变曲线表现为力学损伤。硅烷偶联剂质量分数较大的改性粉煤灰,能够更多地均匀分散、溶入到聚氨酯内,增加了两者交联密度,使得材料相容性更好,应力应变曲线相对较平滑,压缩强度与弹性模量也更大。

Polyurethane/modified fly ash composites were prepared by mixing the modified fly ash and polyurethane composites with different silane coupling agents(KH560). The stress-strain curves of the modified fly ash composites were analyzed in the indoor compression process, and the results were further investigated under the mass fraction of 0.15%, 0.30% and 0.45% silane coupling agents, respectively. Effect of modified fly ash of different quality on compressive strength and elastic modulus of composites. Research results show that the coupling agent mass fraction, the same of modified fly ash mortar is not necessarily a linear increase, composite materials “saturation” phenomenon, will happen too much modified fly ash will organize the continuation of chain extension reaction, affect internal structure, composite materials, in turn, affect the compression performance, stress strain curve of mechanical damage. The modified fly ash with a larger mass fraction of silane coupling agent can be more evenly dispersed and dissolved into polyurethane, which increases the crosslinking density of the two, resulting in better material compatibility, relatively smooth stress-strain curve, and larger compressive strength and elastic modulus.